feat(license): add gyandoot-license crate + CLI subcommand

- New crate: gyandoot-license with:
  - Machine fingerprinting (CPU, MAC, Disk, hostname)
  - Ed25519 JWT signing and verification
  - Agent counting with RAII guards
  - AES-256-GCM encrypted license cache
  - Anti-tamper binary integrity checks
  - Debugger detection
- Added to workspace Cargo.toml
- Added 'gyandoot license' CLI subcommand (activate, status, deactivate, fingerprint)

crates/gyandoot-license/Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "gyandoot-license"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+description = "GyanDoot License Validation — JWT, Machine Binding, Agent Counting"
+
+[dependencies]
+serde.workspace = true
+serde_json.workspace = true
+thiserror.workspace = true
+anyhow.workspace = true
+tracing.workspace = true
+sha2.workspace = true
+hex.workspace = true
+base64.workspace = true
+rand.workspace = true
+chrono.workspace = true
+uuid.workspace = true
+reqwest.workspace = true
+aes-gcm.workspace = true
+
+# JWT
+jsonwebtoken = "9"
+ed25519-dalek = "2"
+
+# Machine fingerprint
+machine-uid = "0.3"